This invention generally relates to the art of fiber optic transmissions and interconnections and, particularly, to optical backplanes.
Optical backplanes are increasingly being used in electronics systems where circuit density is ever-increasing and is difficult to provide with known electrically wired backplanes. An optical backplane is formed by a plurality of optical fibers mounted or routed on a substrate in a given pattern or circuit geometry. Optical backplanes are used to interconnect optical circuit components which transmit signals optically, as well as electrical circuit components, wiring boards, modules and/or integrated circuits. When an optical backplane interconnects electrical components, the electrical energy of each component is translated to optical energy which is transmitted by optical fibers on the optical backplane to another electrical component where it is translated back to electrical energy for transmission to the other electrical component. Optical fibers can transmit much more information than electrical conductors and with significantly less signal degradation.
Optical backplanes are fabricated in a variety of manners, ranging from laying the optical fibers on the substrate by hand to routing the optical fibers in a given pattern onto the substrate by mechanized apparatus. Most such apparatus are complex and expensive to manufacture and are difficult to maintain. The present invention is directed to providing a simple, efficient and reliable apparatus for use in fabricating optical backplanes.
An object, therefore, of the invention is to provide a new and improved apparatus for routing an optical fiber from a supply thereof onto a surface of a substrate which may have an adhesive thereon.
In the exemplary embodiment of the invention, the apparatus includes a routing head which is movable over the surface of the substrate in a given circuit pattern. Drive means is provided for feeding the optical fiber from the supply to the routing head. A feed needle on the routing head receives the optical fiber from the drive means and lays the fiber onto the surface of the substrate at an angle thereto as the routing head moves thereover. The inherent stiffness of the angled optical fiber biases the fiber against the adhesive on the surface of the substrate as the fiber is layed onto the surface in the given circuit pattern.
As disclosed herein, the supply of optical fiber comprises a rotatable reel upon which the optical fiber is wound and off of which the fiber is pulled by the drive means. The feed needle extends at an angle to the surface of the substrate and terminates in a distal end extending generally parallel to the substrate. The distal end has an open channel on the outside thereof facing the surface of the substrate and through which the optical fiber is fed to the surface.
According to one aspect of the invention, the drive means is provided by a pair of drive rollers sandwiching the optical fiber therebetween. Second drive rollers are provided nearer to the feed needle than the pair of drive rollers and establish a fiber loop therebetween.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.